The present invention relates to the art of indicating time using the position of the sun and more particularly to an improved method and means for producing an indication of solar time using the contrast between an illuminated line, formed by sunlight passing through a flat slotted opaque surface, and a darker background on another flat surface.
Horological devices using the position of the sun in the sky have been known since ancient times and have generally involved some means for casting a shadow whose position on a scale provides an indication of the time. Various instruments for this purpose have taken many forms from the simple sundial with its triangular shadow casting member disposed on a circular time-indexed base to more structurally complicated and sophisticated solar clocks such as disclosed in U.S. Pat. No. 3,486,234 to Waterman and U.S. Pat. No. 3,786,570 to Davies.
The present invention presents a simplified method and means for indicating solar time incorporated in a box-like sun clock which may be constructed in various forms to present an illuminated line on a darker background time indication for viewing both indoors and outdoors.